Description_x000D_ Packaging_x000D_ 5, 25 mg in glass bottle_x000D_ Biochem/physiol Actions_x000D_ PF-543 hydrochloride is a novel, cell-permeable, potent and selective inhibitor of sphingosine kinase-1 (SphK1). PF-543 inhibits SphK1 with a Ki of 3.6 nM, is sphingosine competitive and is more than 100-fold selective for SphK1 over the SphK2 isoform. PF-543 decreased the level of endogenous S1P by 10-fold with proportional increase of the level of sphingosine._x000D_ PF-543 stimulates granular accumulation of microtubule-associated protein light chain 3 (LC3). It also induces LC3-I to LC3-II conversion, inhibited by autophagy inhibitors, wortmannin, 3-methyladenine (3-MA) and bafilomycin A1. In human head and neck squamous cell carcinoma (SCC) cells, PF-543 hydrochloride promotes necrosis,apoptosis and autophagy._x000D_ Other Notes_x000D_ This compound was developed by Pfizer for Kinase Phosphatase Biology research. To learn more about Sigma′s partnership with Pfizer and view other authentic, high-quality Pfizer compounds, visit sigma.com/bsm-pfizer._x000D_ To browse the list of other pharma-developed compounds and Approved Drugs/Drug Candidates, click here._x000D_ Legal Information_x000D_ Sold for research purposes under agreement from Pfizer Inc._x000D_ Pfizer is a registered trademark of Pfizer, Inc.